In short: in the 2025 California Wildland-Urban Interface Code (Title 24, Part 7), section 504.9 accepts an exterior door built in any one of six ways: noncombustible construction; solid core wood at least 1 3/4 in thick; solid core wood with stiles and rails at least 1 3/8 in thick and raised panels at least 1 1/4 in thick; a fire protection rating of at least 20 minutes; or an exterior surface that passes ASTM E2707 or SFM Standard 12-7A-1. Glass in a door follows section 504.8, most often multilayered glazing with at least one pane of tempered glass. A solid wood front door can comply on its thickness alone. Your building department has the final word on your permit.
The six ways an exterior door can comply (section 504.9)
- Noncombustible construction, such as a steel door.
- Solid core wood at least 1 3/4 in (44 mm) thick.
- Solid core wood built to two minimums: stiles and rails at least 1 3/8 in (35 mm) thick, and raised panels at least 1 1/4 in (32 mm) thick, with the edge of the panel allowed to taper to a tongue no thinner than 3/8 in (10 mm).
- A fire protection rating of at least 20 minutes, tested to NFPA 252, UL 10B or UL 10C.
- An exterior surface or cladding tested to ASTM E2707 that meets the conditions of section 504.9.3.
- An exterior surface or cladding that meets SFM Standard 12-7A-1.
Glass in the door (section 504.8)
Windows in exterior doors and glazed doors follow the glazing section. It accepts multilayered glazed panels with at least one pane of tempered glass, glass block, glazing with a fire protection rating of at least 20 minutes (NFPA 257 or UL 9), or glazing that meets SFM Standard 12-7A-2. For a wood front door with glass in the arch, the usual answer is an insulated glass unit with a tempered pane.
Garage doors and openers
Section 504.9.2 keeps the gaps around a garage door to 1/8 in or less at the bottom, sides and top, or controls them with tested weather-stripping, door overlaps onto the jambs and header, or metal flashing. Section 504.9.1 requires automatic openers on residential garage doors to have a battery backup.
What this means for a wood front door
- A solid wood door at least 1 3/4 in thick meets the thickness option on its own. Our exterior arched doors are solid wood, 2 1/4 in thick.
- A thinner frame and panel door can still comply under option 3 if its stiles, rails and panels meet the minimums.
- Hollow core and foam core doors need noncombustible construction, a rating or a test listing instead.
- An arch does not change the rule. Glass in the arched top panel follows section 504.8.
What to give the plan checker
A short specification sheet answers most questions: the door species and construction (solid core wood, frame and panel), the overall thickness, the stile, rail and panel thickness if you rely on option 3, and the glazing make-up if the door has glass. When you order a door from us, we send your building department the specifications it asks for.
When to order the front door in a rebuild
Order it once the rough opening is framed and its size is fixed, so the door and its arched frame are built to the real opening rather than the plans. Our doors take 4 to 6 weeks to build, so ordering at framing usually has the door on site before the exterior finish closes up around the opening. For the interior woodwork, see our guide to planning millwork in a Palisades rebuild.
Arched front doors for fire zone rebuilds
Element Decor builds round top and eyebrow arched front doors in solid Sapele mahogany or white oak, 2 1/4 in thick, with weatherstripping, a sill and an exterior rated finish, from $5,000. Prices online are preliminary and confirmed after we check your measurements. Price your door, or see our Pacific Palisades page.
Questions
Do wood front doors meet the WUI code?
Yes, when they are built to one of the options in section 504.9. A solid core wood door at least 1 3/4 in thick is one of them.
Does the WUI code apply to doors inside the house?
No. It covers the outside of the building: roofs, vents, walls, decks, windows and exterior doors. Interior doors and interior woodwork follow the regular building code.
Which code edition applies to my permit?
The edition in force when your permit application is filed, together with any local amendments. Your plan checker has the final word.
This guide summarizes the code text to help with planning. It is not legal advice.
